You would have to absolutely shred the books to get even one to fit into a two-hour time frame.
The adaptations would have to be loose and have many things left out, you're right. However, the majority of the non-canon characters, if not all of the ones not created by David Mack, would probably have to be left out anyway because I doubt the studio would want to pay all the creators of those characters royalties. To remain true to the spirit of each novel, if I was producing these movies, I'd have David Mack either write or co-write the screenplay.
The Mirrorball Man wrote:
Who knows? Speaking for myself, though, I'd have absolutely no interest in seeing such a film. I think while it may make for a nice reading for fans, it would be the wrong direction for the franchise and would probably lead to a rather unsatisfying cinematic experience.
I can't really address your tastes, but if I were given the power to make this adaptation, I would do it as a way of giving that era of Trek the proper sendoff it deserves and other than animated adaptations of the Star Trek: Odyssey trilogy and Star Trek: Countdown, I would do nothing else in that era or most likely any of the 24th century.